I could spend all day watching this channel .
Note: While some of these are better suited to older kids (if you actually expect them to under the concepts behind them) they do have plenty of younger kid appeal to those in to drawing.
A Möbius strip story:
Fractal Doodles!! X2 (Yes, someday I'll get over fractals, I promise. )
In truth, I obsess over these things, because I love mathematics but I hate arithmetic. And the fact that we don't commonly know the difference is the tragedy of math curriculum.